Improvement in skate-frames



.holds all -the parts tightly together.

` instance globular.

` WILLIAM N. BARTHOLOMEW, OF NEWTON CENTRE, MASSACHUSETTS.

Laim Putman. 100,712, dated March 15, 1870.

. IMPROVEMENT IN SIJATE-FRAMES.

Theschedule referred vto il these Letters Patent and making part of the same.

and I hereby declarethe following to'be alfull, clear,

and exact description of the same,.rcference being had to the accompanying drawing, which represents a slateframe made in accordance with my invention.

This invention is directed to theformation of an elastic corner for slate-frames; and Its object is to produce a cheap and durable corner,

which shall have as lirm and permanent connection as l possible with the slate-flame;

To this end, I employ a'globnlar or other suitablyshaped piece oi" rubber or other elastic material, in which is inbeddeda screw whose shank projects from the rubber, and `is adapted to'be screwed into the corner of the frame or into a tenon formed therein for its reception.

A recess around the tenon, whose shape conforms to that of the adjoining portion of the rubber, serves `to partly receive the Arubber corner, and the screw,

after it has entered the properfdistance'into the tenen,

The manner in which my inventionis orv may be ycarried into eiect will be readily understood by reference to the accompanying drawing. -i The elastic corner is vseen at a. piece of vulcanized rubber It consists of a of suitable shape, in this A screw, b, is Vimbedded inthe rubber before vulcanization, and is so arranged that its shank will project from the rubber the proper distance `to'allow it to enter the slate-frame. t i

Around the shank of the screw there is/formedfin the rubber a recess, 'c,` oi' cylindrical or other form, to iit the tenonon the slate-frame.

This tenon is represented at and around it is made a recess,.e, of suc-h shapeas to conform to the shape ofthe adjoining portion of the rubber corner. It will be. observed that the rubber can turn upon the screw,

, so that, when the latter is screwed into the frame, the

rubber corner maybe handled and turned. or twisted without danger oftloosening the screw.

In putt-ing the parts together, the screw b is screwe down into the tenon, carrying the rubber corner with it, until the tenon hasfully entered the recess c and the rubber is drawn into the recess c, so as to be in close contact with the slate-frame.

The parts are nowin proper position, and the rubber'is held firmly and permanently in place.

As the rubber is adapted to turn upon the screw, I. employ, when securing the corner to the frame, a clamping mechanism which will grasp the rubber tightly enough to produce friction between the rubber and screw, suiicient to enable ine to turn the screw into the corner of the frame. It will be noticed thatthe head of the screw extends outward beyond the center ofthe rubber ball, so as to support the same and give 'it the necessarystiilhess. y At times it maybe found advisable to dispense with the tenon andinsert the screw into the recessed corner directly, but I much prefer the arrangement above described. I

Haying now described my invention, and the manner Vin which `the same is or may becarried into effect, 'V What I claim, and desire to secure by Letters Patent, i s- Y An elastic corner for slate-flames, consisting of vulcanized rubber of globular or other suitable shape, in combination with a screw imbedded in said rubber before its vnlcanization, `and adapted to beapplied to the-slate-frame, substantially as shown and set forth.

2. '.lhe combination of the screw and the vulcanized rubber ball, or its equivalent, formed with a recess around the shank of the screw, with the tenon and Arecess in the slateframe, substantially as shown and set forth. l

Y In testimony whereof 'I have signed my name to this specification before two subscribing Witnesses.

WM. N. BAI-THOLOMEW.

Witnesses J onN D. LONG, -WILLIAM BARTLETT. 

